Probably not much time, a lot of packages come with init scripts anyway, and they’re pretty trivial to write if not.
You can certainly argue it’s a philosophical choice, I’d say it’s more down to recognising the many poor architectural choices in systemd, rubbing agaist its many pain points and misfeatures and being alarmed at the size of the attack surface it exposes. I understand there is an effort underway to reduce the size and complexity of the main shared library to help address the last point, but just the fact that is necessary shows the scope of the problem.